post + meta

// WP_Query arguments
$args = array(
	'post_type'              => array( 'post' ),
	's'                      => 'Search Keyword',
	'tax_query'              => array(
		'relation' => 'AND',
		array(
			'taxonomy'         => 'category',
			'terms'            => '5',
			'field'            => 'term_id',
			'operator'         => 'IN',
		),
	),
	'meta_query'             => array(
		'relation' => 'OR',
		array(
			'key'     => 'expiration_date',
			'value'   => '$end',
			'compare' => '<=',
			'type'    => 'NUMERIC',
		),
		array(
			'key'     => 'post_is_extend',
			'value'   => '1',
			'compare' => '=',
			'type'    => 'NUMERIC',
		),
	),
);

// The Query
$query = new WP_Query( $args );

// The Loop
if ( $query->have_posts() ) {
	while ( $query->have_posts() ) {
		$query->the_post();
		// do something
	}
} else {
	// no posts found
}

// Restore original Post Data
wp_reset_postdata();